Which of the following best describes the doctrine of promissory estoppel as established in Central London Property Trust v High Trees House?

Correct answer: A) It prevents a promisor going back on a promise not to enforce strict legal rights where the promisee has relied on it, but it can only be used as a defence

Explanation

Promissory estoppel prevents a party from going back on a promise to waive or suspend rights where the other party has relied on it and it would be inequitable to allow resiling. Combe v Combe confirms that it is 'a shield, not a sword', so it cannot found a cause of action. It usually suspends rather than extinguishes rights, which can often be revived on reasonable notice.